During an angiogram, the doctor inserts a catheter into the blood vessels and injects a contrast material or dye that makes the arteries visible on X-rays, advises Mayfield Clinic. Next, the doctor takes a series of X-ray images to examine the arteries and diagnose conditions including aneurysms or arterial stenosis.
The patient should not eat or drink after midnight the night before the procedure, advises Mayfield Clinic. During the procedure medical staff monitor the patient's heart rate and blood pressure. Doctors usually insert the catheter into the femoral artery, then thread the catheter through the body to an artery in the neck or brain to inject the contrast material.
Alternatively, the doctor inserts the catheter through the leg or arm and guides it to the heart for a coronary angiogram, advises Cleveland Clinic. This allows the doctor to check for coronary artery disease, valve disease and heart muscle function.
In some cases, the doctor performs additional procedures along with the angioplasty. For example, with a balloon angioplasty, after images are taken, a balloon at the tip of the catheter is inflated at the site of the blockage. This compresses the plaque and widens the artery, allowing increased blood flow, states Cleveland Clinic. In some cases, after the balloon procedure, a stent, or a metal mesh tube, is inserted to provide support for the artery and hold the vessel open.